JP6558386B2 - Thermally expandable sheet, method for manufacturing thermally expandable sheet, and method for manufacturing shaped article - Google Patents

Description

The present invention has a thermal expansion sheet to expand by foaming in response to the absorbed heat, a method of manufacturing a manufacturing how and shaped article of the heat-expandable sheet.

  2. Description of the Related Art Conventionally, a thermally expandable sheet is known in which a thermally expandable layer including a thermally expandable material that expands and expands according to the amount of heat absorbed is formed on one surface of a base sheet. By forming a light-to-heat conversion layer that converts light into heat on the thermally expandable sheet and irradiating the light-to-heat conversion layer with light, the heat-expandable layer can be partially or wholly expanded. Moreover, the method of forming a three-dimensional molded item (stereoscopic image) on a thermally expansible sheet | seat by changing the shape of a photothermal conversion layer is also known (for example, refer patent document 1, 2).

JP-A 64-28660 JP 2001-150812 A

  By the way, in the conventional thermally expansible sheet, the surface has yellowishness and there exists a problem that whiteness is low. Such a heat-expandable sheet also has a problem that it is difficult to express a vivid color when a stereoscopic image is formed on the surface thereof.

  Accordingly, there is a need for a thermally expandable sheet having a good whiteness on the surface of the sheet.

The present invention has been made in view of the above, the surface with good whiteness, or the surface of the desired easy intumescent sheet is colored in a color manufacturing method and molded article of the heat-expandable sheet It aims at providing the manufacturing method of.

In order to achieve the above object, a thermally expandable sheet according to the present invention has a base material and a thermal expansion layer formed on one surface of the base material, and is partially on the surface of the thermal expansion layer. A heat-expandable sheet in which irregularities are formed on the surface by applied heat, wherein the heat-expandable layer is formed on the first heat-expandable layer and the first heat-expandable layer. A second thermal expansion layer, and a predetermined white pigment is contained only in the second thermal expansion layer out of the first thermal expansion layer and the second thermal expansion layer. It is characterized by.
Moreover, the thermally expansible sheet of the other aspect which concerns on this invention has a base material and the thermal expansion layer formed on one surface of the said base material, and is partially with respect to the surface of the said thermal expansion layer. A heat-expandable sheet in which irregularities are formed on the surface by heat applied to the heat-expandable sheet, wherein the heat-expandable layer is formed in multiple layers, and is on a side farther from a layer closer to the substrate. The layer is configured so that the content ratio of the predetermined white pigment to the thermally expandable material is increased.

The method for producing a thermally expandable sheet according to the present invention includes a base material and a thermal expansion layer formed on one surface of the base material, and is formed so as to overlap the thermal expansion layer. In the method for producing a thermally expandable sheet, the heat-expanded layer is subjected to heat-expanded by the heat-heat-converted layer and the heat-expanded layer in the portion superimposed on the light-heat-converted layer is thermally expanded. And forming a thermal expansion layer containing a thermally expandable material on one surface of the base material, and the thermal expansion layer formed by the forming step includes: A thermal expansion layer; and a second thermal expansion layer formed on the first thermal expansion layer, wherein the second of the first thermal expansion layer and the second thermal expansion layer. A predetermined white pigment is contained only in the thermal expansion layer .
Moreover, the manufacturing method of the thermally expansible sheet of the other aspect which concerns on this invention is equipped with a base material and the thermal expansion layer formed on the one surface of the said base material, and overlaps with the said thermal expansion layer. A heat-expandable sheet for forming irregularities on the surface by thermally expanding the portion of the heat-expandable layer superimposed on the light-to-heat conversion layer with heat converted by the light-to-heat conversion layer formed as described above A forming step of forming the thermal expansion layer containing the heat-expandable material in multiple layers on one surface of the base material, the forming step being close to the base material The thermal expansion layer is formed in multiple layers by adding the predetermined white pigment so that the content of the predetermined white pigment with respect to the thermally expandable material is larger in the layer farther than the side layer. Forming.
Moreover, the manufacturing method of the molded article which concerns on this invention is the 1st formation step which forms the 1st thermal expansion layer containing the 1st thermal expansion material on one side of a base material, The said 1st A second forming step of forming a second thermally expandable layer containing a second thermally expandable material on the first thermally expanded layer formed by the first forming step; and the second forming step. A third formation step of forming a light-to-heat conversion layer for converting light into heat on the second thermal expansion layer formed by the step, and light to the light-to-heat conversion layer formed by the third formation step By irradiating, heat is generated in the photothermal conversion layer, and the first thermal expansion layer and the second thermal expansion layer in a portion overlapping with the photothermal conversion layer are thermally expanded to form a surface. A fourth forming step for forming irregularities, and the second forming step. Forming the second thermal expansion layer by containing a predetermined white pigment, and forming the first thermal expansion layer without containing the predetermined white pigment in the first formation step. It is characterized by.
According to another aspect of the method for manufacturing a shaped article according to the present invention, a first forming step of forming a plurality of thermally expandable layers containing a thermally expandable material on one surface of a base material, A second formation step of forming a photothermal conversion layer for converting light into heat so as to overlap the thermal expansion layer formed by the formation step of 1, and the photothermal conversion formed by the second formation step A third formation in which irregularities are formed on the surface by generating heat in the photothermal conversion layer by irradiating the layer with light and thermally expanding the portion of the thermal expansion layer overlapping the photothermal conversion layer. And the first forming step is such that the layer farther than the layer closer to the substrate has a predetermined white pigment content ratio to the thermally expandable material. The predetermined white pigment is included so as to increase, Forming an intumescent layer in the multilayer, characterized in that.

ADVANTAGE OF THE INVENTION According to this invention , the surface can provide the whiteness which has favorable whiteness , or can easily color the surface in a desired color, the manufacturing method of a thermally expandable sheet, and the manufacturing method of a molded article can be provided. .

2 is a cross-sectional view schematically showing a thermally expandable sheet according to Embodiment 1. FIG. 3 is a cross-sectional view schematically showing a method for producing a thermally expandable sheet according to Embodiment 1. FIG. 1 is a diagram illustrating an overview of a stereoscopic image forming system according to Embodiment 1. FIG. 3 is a flowchart illustrating a stereoscopic image forming process according to the first embodiment. 3 is a cross-sectional view schematically showing a stereoscopic image forming process according to Embodiment 1. FIG. It is sectional drawing which shows the comparison with a comparative example and the thermal expansion layer of this embodiment. It is sectional drawing which shows typically the thermally expansible sheet which concerns on Embodiment 2. FIG.

  Hereinafter, a thermally expandable sheet and a method for producing a thermally expandable sheet according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the thermally expandable sheet 10 according to Embodiment 1 includes a base material 11, a first thermally expandable layer 12, a second thermally expandable layer 13, and an ink receiving layer 14. The first thermal expansion layer 12 and the second thermal expansion layer 13 constitute a thermal expansion layer of the thermally expandable sheet 10. In addition, as will be described in detail later, the thermally expandable sheet 10 is printed by the three-dimensional image forming system 50 schematically shown in FIGS. 3A to 3C and has a surface with irregularities on the surface. (Stereoscopic image) is formed.

  The base material 11 is a sheet-like member that supports the thermal expansion layer. As the substrate 11, paper such as high-quality paper, medium-quality paper, and synthetic paper, or a commonly used plastic film such as polypropylene, polyethylene terephthalate (PET), or polybutylene terephthalate (PBT) is used. Moreover, the base material 11 is on the opposite side (lower side shown in FIG. 1) of the base material 11 when the first thermal expansion layer 12 and the second thermal expansion layer 13 are expanded entirely or partially by foaming. It does not bulge and has a strength that does not cause wrinkles or undulations. In addition, it has heat resistance to withstand heating when foaming the thermal expansion layer. The thickness of the base material 11 is, for example, about 200 μm.

  The first thermal expansion layer 12 is formed on one surface (the upper surface shown in FIG. 1) of the substrate 11. The first thermal expansion layer 12 is a layer that expands to a size corresponding to the heating temperature and the heating time, and a plurality of thermally expandable materials MC1 (thermally expandable microcapsules and microcapsules) are dispersed in the binder B1. Has been placed. As will be described later, the second expansion layer 13 includes a white pigment, but the first expansion layer 12 does not include a white pigment. Further, as will be described in detail later, in the present embodiment, a photothermal conversion layer is formed on the ink receiving layer 14 provided on the upper surface (front surface) of the base material 11 and / or on the lower surface (back surface) of the base material 11. By irradiating light, the region provided with the photothermal conversion layer is heated. The first thermal expansion layer 12 absorbs heat generated in the photothermal conversion layer on the front surface and / or the back surface and foams and expands, so that only a specific region can be selectively expanded. The thickness of the first thermal expansion layer is, for example, about 100 μm.

  As the binder B1, a thermoplastic resin selected from vinyl acetate polymers, acrylic polymers and the like is used. The thermally expandable microcapsule MC1 is obtained by encapsulating propane, butane, or other low boiling point vaporizable substance in a thermoplastic resin shell. The shell is formed of a thermoplastic resin selected from, for example, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic ester, polyacrylonitrile, polybutadiene, or a copolymer thereof. The average particle size of the thermally expandable microcapsule is about 5 to 50 μm. When this microcapsule is heated to a temperature higher than the thermal expansion start temperature, the polymer shell made of resin is softened, the encapsulated low-boiling vaporizable substance is vaporized, and the capsule expands due to the pressure. Although depending on the characteristics of the microcapsule used, the microcapsule expands to about 5 times the particle size before expansion. In FIG. 1, for convenience, the particle diameters of the microcapsules MC1 are shown to be approximately the same, but actually, the particle diameters of the microcapsules MC1 vary, and all the microcapsules have the same particle diameter. Do not mean.

  The second thermal expansion layer 13 is formed on the first thermal expansion layer 12 formed on one surface of the substrate 11. Similarly to the first thermal expansion layer 12, the second thermal expansion layer 13 is a layer that expands to a size corresponding to the heating temperature and the heating time, and the thermal expansion material MC2 (thermal expansion) in the binder B2. Microcapsules) are dispersedly arranged. The second thermal expansion layer 13 includes a white pigment W as shown in FIG. As the white pigment W, a material selected from titanium oxide, barium sulfate, zinc oxide and the like can be used, and titanium oxide is particularly preferable. When the second thermal expansion layer 13 contains a white pigment, the whiteness of the thermal expansion layer can be improved. For the binder B2 and the thermally expandable microcapsule MC2, the materials mentioned as the binder B1 and the thermally expandable microcapsule MC1 of the first thermally expandable layer 12 are used. The binder B2 and the thermally expandable microcapsule MC1 may be made of a different material or the same material as the binder B1 and the thermally expandable microcapsule MC1 of the first thermally expandable layer 12, respectively. It is preferable to use the same material for the first thermal expansion layer 12 and the second thermal expansion layer 13 because the raw materials are made common, the manufacturing process can be simplified, and in addition, the manufacturing cost can be reduced. Similarly to the first thermal expansion layer 12, the second thermal expansion layer 13 absorbs heat generated in the light-to-heat conversion layer formed on the upper surface and / or the lower surface of the base material 11, expands, and expands. To do.

  In the second thermal expansion layer 13, the ratio (also referred to as content) of the thermal expansion material MC2 contained in the binder B2 is the thermal expansion coefficient relative to the binder B1 in the first thermal expansion layer 12. The ratio (also referred to as a content ratio) in which the material MC1 is contained may be the same or may be lowered. FIG. 1 illustrates an example in which the content ratio of the thermally expandable material MC2 with respect to the binder B2 is lower than that of the first thermally expanded layer 12. Here, the ratio of the thermally expandable material to the binder is defined using a volume ratio, a weight ratio, and the like. For example, when the weight ratio is used, the weight ratio (second ratio) of the thermally expandable material MC2 to the binder B2 is the same as the weight ratio (first ratio) of the thermally expandable material MC1 to the binder B1. is there. Alternatively, the second ratio is smaller than the first ratio, specifically about 1/3 to 1/8. In other words, for example, the heat-expandable material MC2 dispersed in 100 parts by weight of the binder B2 is X2 parts by weight, and the heat-expandable material MC1 dispersed in 100 parts by weight of the binder B1 is X1 by weight. X2 / X1 is the same as 1 or about 1/3 to 1/8. In addition, the ratio in which a thermally expansible material contains with respect to a binder may be defined by the density. In this case, it can be said that the second thermal expansion layer 13 contains the thermally expandable material at the same density or at a lower density than the first thermal expansion layer 12.

  The thickness of the second expansion layer 13 may be the same as the thickness of the first expansion layer 12 or may be thinner than the first expansion layer 12.

  In the case where the content of the thermally expandable material is lowered in the second expanded layer 13, the second expanded layer 13 obtains a height when expanded compared to the first thermally expanded layer 12. Therefore, it is preferable that the first thermal expansion layer 12 be formed thinner than the first thermal expansion layer 12. The second thermal expansion layer 13 is preferably not formed thicker than necessary. Therefore, the second thermal expansion layer 13 is formed to have a thickness corresponding to several thermal expansion materials MC2, for example, a thickness corresponding to 1 to 10, preferably 1 to 5. preferable. In other words, it is preferably formed to a thickness of 1 to 10 times, preferably 1 to 5 times the average particle size of the microcapsules. For example, the second thermal expansion layer 13 is formed to a thickness of about 50 μm.

  The ink receiving layer 14 is formed on the second thermal expansion layer 13 formed on one surface of the substrate 11. The ink receiving layer 14 is a layer that receives and fixes ink used in a printing process, for example, ink of an ink jet printer. The ink receiving layer 14 is formed using a widely used material according to the ink used in the printing process. For example, when water-based ink is used, the ink receiving layer 14 is formed using a material selected from porous silica, polyvinyl alcohol (PVA), and the like. It is preferable to use a white material such as porous silica for the ink receiving layer 14 because the whiteness of the surface of the thermally expandable sheet 10 can be further improved. Note that the ink receiving layer 14 may be omitted when an ultraviolet curable ink is used in an inkjet method. In addition, when a material that does not easily receive ink, such as a plastic film, is used as the base material 11 and a photothermal conversion layer is formed on the back side of the base material 11, the ink receiving layer is also formed on the other surface (lower surface) of the base material 11. Is preferably provided.

  In the thermally expandable sheet 10 of the present embodiment, as will be described later in detail, the white expandable sheet 13 contains the white pigment W in the second expandable layer 13 provided on the first expandable layer 12, whereby the thermally expandable sheet. It is possible to improve the whiteness of the 10 surface. In the present embodiment, the surface of the thermally expandable sheet or the surface of the sheet indicates the surface of the thermally expandable sheet 10 on the side where the first thermally expandable layer 12 or the like is provided. Therefore, according to this embodiment, when the thermally expandable sheet 10 is viewed from the side where the first thermally expandable layer 12 and the like are provided, it can be said that the apparent whiteness of the thermally expandable sheet 10 is improved.

(Method for producing thermally expandable sheet)
Next, the manufacturing method of the thermally expansible sheet | seat 10 is demonstrated using FIG. 2 (a)-FIG.2 (c).
First, a sheet-like material, paper, or the like is prepared as the base material 11. The base material 11 may be a roll shape or may be cut in advance.

  Next, a binder made of a thermoplastic resin or the like and a thermally expandable material (thermally expandable microcapsule) are mixed to prepare a coating liquid for forming the first thermally expandable layer 12.

  Subsequently, the coating liquid is applied onto the substrate 11 using a known coating apparatus such as a bar coater, a roller coater, or a spray coater. Subsequently, the coating film is dried to form the first thermal expansion layer 12 as shown in FIG. In addition, in order to obtain the target thickness of the first thermal expansion layer 12, the coating liquid may be applied and dried a plurality of times.

  Next, a coating liquid for forming the second thermal expansion layer 13 is prepared by mixing the binder and the thermal expansion material. The binder and the thermally expandable material may be different from the coating liquid for forming the first thermally expanded layer 12, but it is preferable to use the same material. At this time, the content of the heat-expandable material with respect to the binder may be the same as the content of the heat-expandable material with respect to the binder in the first heat-expandable layer 12, and is lower than that, for example, 1/3 to 3 by weight ratio. It may be about 1/8. In addition, a white pigment, for example, a material selected from titanium oxide, barium sulfate, zinc oxide and the like is mixed in the coating solution.

  Then, the coating liquid for forming the 2nd thermal expansion layer 13 is apply | coated on the 1st thermal expansion layer 12 using the well-known coating device by systems, such as a bar coater, a roller coater, and a spray coater. Next, the coating film is dried to form a second thermal expansion layer 13 as shown in FIG. In addition, in order to obtain the target thickness of the second thermal expansion layer 13, coating and drying may be performed a plurality of times. Here, the second thermal expansion layer 13 may have the same thickness as the first expansion layer 12 or may be thinner than the first expansion layer 12. In the case where the content ratio of the heat-expandable material is lowered in the second expansion layer 13, the second expansion layer 13 is preferably formed thinner than the first thermal expansion layer 12. The second thermal expansion layer 13 is formed to have a thickness corresponding to several thermal expansion materials MC2, for example, a thickness corresponding to 1 to 10, preferably 1 to 5. preferable.

  Next, a material constituting the ink receiving layer 1, for example, a material selected from porous silica, PVA and the like is dispersed in a solvent to prepare a coating liquid for forming the ink receiving layer. Subsequently, this coating solution is applied onto the second thermal expansion layer 13 by using a known coating apparatus such as a bar coater, a roller coater, or a spray coater. Subsequently, the coating film is dried to form an ink receiving layer 14 as shown in FIG. When the roll-shaped base material 11 is used, it is cut into a size suitable for the stereoscopic image forming system 50.

  The thermally expandable sheet 10 is manufactured by the above process.

(3D image forming system)
Next, the three-dimensional image forming system 50 that forms a three-dimensional image on the thermally expandable sheet 10 of the present embodiment will be described. As shown in FIGS. 3A to 3C, the stereoscopic image forming system 50 includes a control unit 51, a printing unit 52, an expansion unit 53, a display unit 54, a top plate 55, and a frame 60. And comprising. 3A is a front view of the stereoscopic image forming system 50, FIG. 3B is a plan view of the stereoscopic image forming system 50 in a state where the top plate 55 is closed, and FIG. FIG. 3 is a plan view of the stereoscopic image forming system 50 in a state where a top plate 55 is opened. 3A to 3C, the X direction is the same as the horizontal direction, the Y direction is the same as the conveyance direction D in which the sheet is conveyed, and the Z direction is the same as the vertical direction. is there. The X direction, the Y direction, and the Z direction are orthogonal to each other.

  The control unit 51, the printing unit 52, and the expansion unit 53 are placed in the frame 60 as shown in FIG. Specifically, the frame 60 includes a pair of substantially rectangular side plates 61 and a connecting beam 62 provided between the side plates 61, and a top plate 55 is passed above the side plates 61. Further, the printing unit 52 and the expansion unit 53 are installed side by side in the X direction on the connection beam 62 passed between the side plates 61, and the control unit 51 is fixed under the connection beam 62. The display unit 54 is embedded in the top plate 55 so that the height coincides with the top surface of the top plate 55.

  The control unit 51 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, and controls the printing unit 52, the expansion unit 53, and the display unit 54.

  The printing unit 52 is an ink jet printing apparatus. As shown in FIG. 3C, the printing unit 52 includes a carry-in unit 52 a for carrying in the thermally expandable sheet 10 and a discharge unit 52 b for discharging the thermally expandable sheet 10. The printing unit 52 prints the designated image on the front or back surface of the thermally expandable sheet 10 carried in from the carry-in section 52a, and discharges the thermally expandable sheet 10 on which the image has been printed from the discharge section 52b. The printing unit 52 includes color inks (cyan (C), magenta (M), yellow (Y)) for forming a color ink layer 42, which will be described later, and a front side photothermal conversion layer 41 and a back side photothermal conversion layer. And black ink (including carbon black). In order to form a black or gray color in the color ink layer 42, a black color ink not containing carbon black may be further provided as the color ink.

  The printing unit 52 acquires color image data indicating a color image (color ink layer 42) to be printed on the surface of the thermally expandable sheet 10 from the control unit, and based on the color image data, color ink (cyan, magenta, yellow). ) Is used to print a color image (color ink layer 42). The black or gray color of the color ink layer 42 is formed by mixing three colors of CMY, or is formed by further using black color ink not containing carbon black.

  Moreover, the printing unit 52 prints the front side photothermal conversion layer 41 using black ink based on the surface foaming data which is data indicating the portion to be foamed and expanded on the surface of the thermally expandable sheet 10. Similarly, the back side photothermal conversion layer 43 is printed using black ink based on back surface foaming data, which is data indicating a portion to be foamed and expanded on the back surface of the thermally expandable sheet 10. Black ink containing carbon black is an example of a material that converts light into heat. The higher the density of the black ink, the higher the expansion height of the thermal expansion layer. For this reason, the density of the black ink is determined so as to correspond to the target height.

  The expansion unit 53 is an expansion device that applies heat to the thermally expandable sheet 10 to expand it. As shown in FIG. 3C, the expansion unit 53 includes a carry-in portion 53 a for carrying in the thermally expandable sheet 10 and a discharge portion 53 b for discharging the thermally expandable sheet 10. The expansion unit 53 applies heat to the thermally expandable sheet 10 carried in from the carry-in part 53a to expand it, and discharges the expanded thermally expandable sheet 10 from the discharge part 53b. The expansion unit 53 includes an irradiation unit (not shown) inside. An irradiation part is a halogen lamp, for example, and is a near infrared region (wavelength 750-1400 nm), visible light region (wavelength 380-750 nm), or mid-infrared region (wavelength 1400-4000 nm) with respect to the thermally expandable sheet 10. ). When light is applied to the heat-expandable sheet 10 on which black ink containing carbon black is printed, light is converted into heat more efficiently in the portion where the black ink is printed than in the portion where the black ink is not printed. Is done. Therefore, in the thermal expansion layer (the first thermal expansion layer and the second thermal expansion layer), the area where the black ink is printed is mainly heated. As a result, the thermal expansion layer is printed with the black ink. The area is expanded.

  The display unit 54 includes a touch panel or the like. For example, as shown in FIG. 3B, the display unit 54 displays an image (star shown in FIG. 3B) printed on the thermally expandable sheet 10 by the printing unit 52. The display unit 54 displays an operation guide or the like, and the user can operate the stereoscopic image forming system 50 by touching the display unit 54.

(Stereoscopic image formation processing)
Next, with reference to the flowchart shown in FIG. 4 and the cross-sectional views of the thermally expandable sheet 10 shown in FIGS. 5A to 5E, a stereoscopic image is formed on the thermally expandable sheet 10 by the stereoscopic image forming system 50. A flow of processing to be formed will be described.

  First, the user prepares the thermally expandable sheet 10 before the stereoscopic image is formed, and designates color image data, front surface foam data, and back surface foam data via the display unit 54. Then, the thermally expandable sheet 10 is inserted into the printing unit 52 with the surface thereof facing upward. The printing unit 52 prints the photothermal conversion layer (front side photothermal conversion layer 41) on the surface of the inserted thermally expandable sheet 10 (step S1). The front side photothermal conversion layer 41 is a layer formed of a material that converts light into heat, specifically, black ink containing carbon black. The printing unit 52 ejects black ink containing carbon black onto the surface of the thermally expandable sheet 10 in accordance with the designated surface foaming data. As a result, a front side photothermal conversion layer 41 is formed on the ink receiving layer 14 as shown in FIG. For ease of understanding, the front-side photothermal conversion layer 41 is illustrated as being formed on the ink receiving layer 14, but more accurately black ink is received in the ink receiving layer 14. Therefore, the front side photothermal conversion layer 41 is formed in the ink receiving layer 14.

  Secondly, the user inserts the thermally expandable sheet 10 on which the front side photothermal conversion layer 41 is printed into the expansion unit 53 with the surface thereof facing upward. The expansion unit 53 heats the inserted thermally expandable sheet 10 from the surface. If demonstrating it concretely, the expansion | swelling unit 53 will irradiate light to the surface of the thermally expansible sheet 10 by an irradiation part (step S2). The front side photothermal conversion layer 41 printed on the surface of the thermally expandable sheet 10 generates heat by absorbing the irradiated light. As a result, as shown in FIG. 5B, the region where the photothermal conversion layer 41 of the thermally expandable sheet 10 is printed rises and expands. Further, in FIG. 5B, when the density of the black ink of the photothermal conversion layer 41 shown on the right is made higher than that of the photothermal conversion layer 41 shown on the left, as shown in the drawing, the darkly printed region becomes higher. It can be inflated.

  Third, the user inserts the thermally expandable sheet 10 whose surface has been heated and expanded into the printing unit 52 with the surface facing upward. The printing unit 52 prints a color image (color ink layer 42) on the surface of the inserted thermally expandable sheet 10 (step S3). Specifically, the printing unit 52 ejects cyan C, magenta M, and yellow Y ink onto the surface of the thermally expandable sheet 10 in accordance with the designated color image data. As a result, a color ink layer 42 is formed on the ink receiving layer 14 and the photothermal conversion layer 41 as shown in FIG.

  Fourth, the user inserts the thermally expandable sheet 10 on which the color ink layer 42 is printed into the expansion unit 53 with the back surface thereof facing upward. The expansion unit 53 heats the inserted thermally expandable sheet 10 from the back surface, and dries the color ink layer 42 formed on the surface of the thermally expandable sheet 10 (step S4). Specifically, the expansion unit 53 causes the irradiation unit to irradiate the back surface of the thermally expandable sheet 10 with light, heats the color ink layer 42, and volatilizes the solvent contained in the color ink layer 42.

  Fifth, the user inserts the thermally expandable sheet 10 on which the color ink layer 42 is printed into the printing unit 52 with the back surface thereof facing up. The printing unit 52 prints the photothermal conversion layer (back side photothermal conversion layer 43) on the back side of the inserted thermally expandable sheet 10 (step S5). Similar to the front side photothermal conversion layer 41 printed on the surface of the thermally expandable sheet 10, the back side photothermal conversion layer 43 is a layer formed of a material that converts light into heat, specifically black ink containing carbon black. It is. The printing unit 52 ejects black ink containing carbon black on the back surface of the thermally expandable sheet 10 in accordance with the designated back surface foaming data. As a result, a photothermal conversion layer 43 is formed on the back surface of the base material 11 as shown in FIG. Also for the backside photothermal conversion layer 43, when the density of the black ink of the photothermal conversion layer 43 shown on the left is made higher than that of the photothermal conversion layer 43 shown on the right, the darkly printed region is expanded higher as shown in the figure. It becomes possible.

  Sixth, the user inserts the thermally expandable sheet 10 on which the back side light-to-heat conversion layer 43 is printed into the expansion unit 53 with its back surface facing upward. The expansion unit 53 heats the inserted thermally expandable sheet 10 from the back surface. If it demonstrates concretely, the expansion | swelling unit 53 will irradiate light to the back surface of the thermally expansible sheet 10 by an irradiation part (not shown) (step S6). The photothermal conversion layer 43 printed on the back surface of the thermally expandable sheet 10 generates heat by absorbing the irradiated light. As a result, as shown in FIG.5 (e), the area | region in which the photothermal conversion layer 43 of the thermally expansible sheet 10 was printed rises and expand | swells.

  A three-dimensional image is formed on the thermally expandable sheet 10 by the procedure as described above.

  According to the thermally expandable sheet and the method for producing the thermally expandable sheet of the present embodiment, the second thermally expandable layer 13 provided on the first thermally expandable layer 12 contains white pigment, The whiteness of the surface of the expandable sheet 10 can be improved. Furthermore, when the ink receiving layer 14 containing a white material such as porous silica is formed on the second thermal expansion layer 13, the whiteness of the surface of the thermal expansion sheet 10 can be further improved. In the present embodiment, in particular, the first thermal expansion layer 12 does not contain a white pigment, and the second thermal expansion layer 13 contains a white pigment. It can prevent that the ratio in which an electroconductive material is contained is reduced with a white pigment, and can prevent reducing the expandable height of the 1st thermal expansion layer 12. FIG. In addition, it is possible to avoid dispersing the white pigment in the ink receiving layer 14 located on the outermost surface of the thermally expandable sheet 10, and it is possible to prevent the ink receiving layer 14 from lowering the performance of receiving ink. Furthermore, since the second thermal expansion layer 13 itself foams and expands, the second thermal expansion layer 13 can also contribute to an increase in the height of the entire thermal expansion layer. As described above, the second thermal expansion layer 13 containing the thermal expansion material is further provided, and the white pigment W is dispersed in this layer. The whiteness of the sheet surface can be improved while contributing to an increase in the overall height of the expanded layer.

  In addition to the above, by reducing the content of the heat-expandable material in the second heat-expandable layer as compared with the first heat-expandable layer, the occurrence of unevenness on the surface of the heat-expandable layer is alleviated, and the heat-expandable It is also possible to smoothly smooth the surface of the adhesive sheet and to have good scratch resistance. For example, as a comparative example, FIG. 6A schematically shows a configuration in which only the first thermal expansion layer, in other words, a thermal expansion sheet not including the second thermal expansion layer is expanded. In this configuration, as shown in FIG. 6A, the microcapsules aggregate on the surface of the thermal expansion layer, and unevenness of the step d1 occurs on the surface. In addition, the microcapsules located on the surface of the thermal expansion layer are easily peeled off as shown in the figure and have poor scratch resistance. On the other hand, in the thermally expandable sheet shown in FIG. 6B that has the same configuration as the present embodiment, the second thermally expanded layer is not formed with a layer having rigidity just like the base material. Therefore, it expands not only in the upward direction but also in the downward direction. Thereby, it is possible to fill the unevenness generated in the first thermal expansion layer by the expansion of the second thermal expansion layer, and the generation of the unevenness on the surface of the first thermal expansion layer is also suppressed. Further, since the amount of microcapsules contained in the second thermal expansion layer is small, the aggregation of macrocapsules is suppressed on the surface of the second thermal expansion layer. Therefore, the level difference d2 generated on the surface of the second thermal expansion layer is suppressed to be smaller than that of the level difference d1, and in the configuration of the present embodiment, compared with the configuration without the second thermal expansion layer, the surface is smooth. Improves the scratch resistance. The ink receiving layer is a layer for receiving and fixing ink on the surface of the thermally expandable sheet. By providing this layer on the second thermally expandable layer, the surface of the thermally expandable sheet is further increased. It is smoothed well and the scratch resistance is further improved.

(Embodiment 2)
A thermally expandable sheet 20 according to Embodiment 2 will be described with reference to the drawings. The thermally expandable sheet 20 according to Embodiment 2 is different from the thermally expandable sheet 10 according to Embodiment 1 in that a third thermally expandable layer 21 is provided between the first thermally expandable layer 12 and the substrate 11. It is in the point provided with. In other words, in this embodiment, the 1st thermal expansion layer 12, the 2nd thermal expansion layer 13, and the 3rd thermal expansion layer 21 comprise a thermal expansion layer. Parts having the same configurations as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 7, the third thermal expansion layer 21 is formed between the base material 11 and the first thermal expansion layer 12. Similar to the first thermal expansion layer 12, the third thermal expansion layer 21 has a thermal expansion material MC3 (thermal expansion microcapsule) dispersedly disposed in the binder B <b> 3. The third thermal expansion layer 21, like the first thermal expansion layer 12, absorbs heat generated in the light-to-heat conversion layer formed on the upper surface and / or lower surface of the thermally expandable sheet 20, expands, and expands. To do. Further, the binder B3 and the thermally expandable material MC3 of the third thermal expansion layer 21 may be different from the binder and the microcapsule of the first thermal expansion layer 12 and the second thermal expansion layer 13, respectively. Although it is good, it is preferable to use the same material.

  In the third thermal expansion layer 21, the ratio (third ratio) of the thermal expansion material MC3 to the binder B3 is such that the first thermal expansion layer 11 has a thermal expansion coefficient with respect to the binder B1. It is made lower than the ratio (first ratio) in which the material MC1 is contained. Similar to the first embodiment, the proportion of the thermally expandable material MC3 contained in the binder B3 is defined using a volume ratio, a weight ratio, or the like. For example, when the weight ratio is used, the weight ratio of the thermally expandable material MC3 to the binder B3 is smaller than the weight ratio of the thermally expandable material MC1 to the binder B1, specifically, 1/3 to 1/8. Degree. In other words, for example, X3 parts by weight of the thermally expandable material MC3 dispersed with respect to 100 parts by weight of the binder B3, and X1 parts by weight of the thermally expandable material MC1 dispersed with respect to 100 parts by weight of the binder B1. Then, X3 / X1 is smaller than 1 and is about 1/3 to 1/8. The ratio of the thermally expandable material to the binder may be defined by the density. In this case, the third thermally expanded layer 21 has a lower density than the first thermally expanded layer 12. Thus, it can be said that it contains a thermally expandable material.

  The thermally expandable sheet 20 of the second embodiment may further suppress the peeling of the thermal expansion layer from the base material 11 when the thermal expansion layer is expanded by further providing the third thermal expansion layer 21. It becomes possible. The third thermal expansion layer 21 has a low content of the thermally expandable material as compared with the first thermal expansion layer 12 and is difficult to obtain a height when expanded. It is preferably formed thinner than the layer 12. The third thermal expansion layer 21 is preferably not formed thicker than necessary.

Next, a method for manufacturing the thermally expandable sheet 20 according to Embodiment 2 will be described.
First, the base material 11 is prepared. Next, a coating solution for forming the third thermal expansion layer 21 is prepared. A thermal expansion material is dispersed in a binder using a known dispersion device to prepare a coating liquid for forming the third thermal expansion layer 21. As the binder and the thermally expandable material, it is preferable to use the same materials as those used for the coating liquid for forming the first thermally expanded layer 12. At this time, the content of the thermally expandable material with respect to the binder in the third thermal expansion layer 21 is set lower than the content of the thermally expandable material with respect to the binder in the first thermal expansion layer 12. For example, the weight ratio is about 1/3 to 1/8. Subsequently, using a known coating apparatus such as a bar coater, a roller coater, or a spray coater, the coating solution is applied onto the substrate, and then the coating film is dried. The application and drying may be performed in a plurality of times, and the third thermal expansion layer 21 having a target thickness is formed on the substrate 11.

Subsequently, a coating liquid for forming the first thermal expansion layer 12 is prepared in the same manner as in the first embodiment, and the coating liquid is applied onto the third thermal expansion layer 31 using a known coating apparatus. And dried to form the first thermal expansion layer 12. Thereafter, as in the first embodiment, the second thermal expansion layer 13 and the ink receiving layer 14 are formed.
Thereby, the thermally expansible sheet 20 which concerns on Embodiment 2 is manufactured.

  In general, in a thermally expandable sheet, a thermal expansion layer provided on a base material expands in a direction opposite to the surface on which the base material is provided (for example, an upward direction shown in FIG. 7). Due to this expansion, peeling may occur between the base material and the thermal expansion layer provided immediately above the base material. In general, the higher the content of the heat-expandable material, the easier it is to peel off from the substrate. On the other hand, in the thermally expandable sheet 20 of the present embodiment, the third content of the thermally expandable material is lower than that of the first thermally expandable layer 12 between the base material 11 and the first thermally expandable layer 12. The thermal expansion layer 21 is interposed. Since the degree of foaming and expansion of the third thermal expansion layer 21 is suppressed as compared with the first thermal expansion layer 12, the thermal expansion layer can be prevented from peeling from the base material 11. . In addition, since the third thermal expansion layer 21 itself expands, the third thermal expansion layer 21 also has an effect of contributing to an increase in the height of the entire thermal expansion layer.

The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.
For example, the above-described embodiments can be appropriately combined.

  In the above-described embodiment, the configuration in which printing is performed in the process illustrated in FIG. 4 has been described as an example. However, the configuration is not limited thereto. For example, the order in which processes are performed can be changed as appropriate. For example, after forming a photothermal conversion layer on both sides of the substrate and forming a color ink layer, it is also possible to irradiate light from the front side and the back side of the substrate to expand the thermal expansion layer.

  Further, in each of the above-described embodiments, the configuration in which the photothermal conversion layer is formed on both the front surface and the back surface is described as an example, but the present invention is not limited to this. The photothermal conversion layer may be formed only on the front surface or only on the back surface according to the use of the printed matter and the printing method. In addition, when printing only on the surface, the ink receiving layer should just be formed in the surface at least.

  Moreover, you may provide an adhesive agent and a release paper in the back surface of a base material according to the use of printed matter, for example using it as a seal | sticker. In this case, a layer made of an adhesive is formed on the back surface of the substrate, and a release paper is provided thereon. The ink receiving layer may be provided on the release paper.

  Although several embodiments of the present invention have been described, the present invention is included in the invention described in the claims and the equivalents thereof. Hereinafter, the invention described in the scope of claims of the present application will be appended.

[Appendix 1]
A first thermal expansion layer formed on one side of the substrate and containing a first thermal expansion material;
A second thermal expansion layer formed on the first thermal expansion layer and containing a second thermal expansion material,
The second thermal expansion layer further includes a white pigment.
A thermally expandable sheet characterized by that.
[Appendix 2]
A first thermal expansion layer formed on one side of the substrate and containing a first thermal expansion material;
A second thermal expansion layer formed on the first thermal expansion layer and containing a second thermal expansion material,
The second thermal expansion layer includes titanium oxide.
A thermally expandable sheet characterized by that.
[Appendix 3]
An ink receiving layer for receiving ink is provided on the second thermal expansion layer.
The heat-expandable sheet according to supplementary note 1 or 2, characterized in that.
[Appendix 4]
The ink receiving layer comprises porous silica;
The thermally expandable sheet according to Supplementary Note 3, wherein
[Appendix 5]
The thickness of the second thermal expansion layer is formed thinner than the thickness of the first thermal expansion layer.
The heat-expandable sheet according to any one of appendices 1 to 4, characterized in that:
[Appendix 6]
The first thermally expandable material and the second thermally expandable material are the same material.
The heat-expandable sheet according to any one of appendices 1 to 5, characterized in that:
[Appendix 7]
The first thermally expandable material and the second thermally expandable material are microcapsules containing a vaporizable substance in a shell,
The thickness of the second thermal expansion layer is a thickness corresponding to several of the microcapsules,
The thermally expandable sheet according to any one of supplementary notes 1 to 6, wherein
[Appendix 8]
Forming a first thermal expansion layer containing a first thermal expansion material on one surface of the substrate;
Forming a second thermal expansion layer containing a second thermal expansion material on the first thermal expansion layer, and
In the step of forming the second thermal expansion layer, a white pigment is included.
A method for producing a thermally expandable sheet, characterized in that
[Appendix 9]
Forming a first thermal expansion layer containing a first thermal expansion material on one surface of the substrate;
Forming a second thermal expansion layer containing a second thermal expansion material on the first thermal expansion layer, and
In the step of forming the second thermal expansion layer, titanium oxide is included.
A method for producing a thermally expandable sheet, characterized in that
[Appendix 10]
Forming a thickness of the second thermal expansion layer thinner than a thickness of the first thermal expansion layer;
The method for producing a thermally expandable sheet according to Supplementary Note 8 or 9, wherein:
[Appendix 11]
Forming an ink receiving layer for receiving ink on the second thermal expansion layer;
The method for producing a thermally expandable sheet according to Supplementary Note 8 or 9, wherein:

  INDUSTRIAL APPLICABILITY The present invention can be used for a thermally expandable sheet that expands according to the amount of heat absorbed and a method for producing the thermally expandable sheet.

DESCRIPTION OF SYMBOLS 10,20 ... Thermal expansion sheet, 11 ... Base material, 12 ... 1st thermal expansion layer, 13 ... 2nd thermal expansion layer, 14 ... Ink receiving layer, 21. ..Third thermal expansion layer, 41 ... front side photothermal conversion layer, 42 ... color ink layer, 43 ... back side photothermal conversion layer, 50 ... stereoscopic image forming system, 51 ... control unit , 52... Printing unit, 52 a, 53 a, carry-in section, 52 b, 53 b, discharge section, 53, expansion unit, 54, display unit, 55, top plate, 60. -Frame, 61 ... side plate, 62 ... connecting beam, B1, B2, B3 ... binder, MC1, MC2, MC3 ... thermal expansion material

Claims (12)

Heat that has a base material and a thermal expansion layer formed on one surface of the base material, and that is unevenly formed on the surface by heat partially applied to the surface of the thermal expansion layer An inflatable sheet,
The thermal expansion layer is
A first thermal expansion layer, and a second thermal expansion layer formed on the first thermal expansion layer ,
A predetermined white pigment is contained only in the second thermal expansion layer of the first thermal expansion layer and the second thermal expansion layer .
A thermally expandable sheet characterized by that. The thickness of the second thermal expansion layer is formed thinner than the thickness of the first thermal expansion layer,
The thermally expandable sheet according to claim 1. The first thermally expandable material contained in the first thermally expandable layer and the second thermally expandable material contained in the second thermally expandable layer are the same material.
The thermally expandable sheet according to claim 1, wherein the sheet is thermally expandable. The first thermal expansion material contained in the first thermal expansion layer and the second thermal expansion material contained in the second thermal expansion layer include a vaporizable substance in the shell. A microcapsule containing,
The thickness of the second thermal expansion layer is a thickness corresponding to several of the microcapsules,
The thermally expandable sheet according to any one of claims 1 to 3, wherein the sheet is thermally expandable. Heat that has a base material and a thermal expansion layer formed on one surface of the base material, and that is unevenly formed on the surface by heat partially applied to the surface of the thermal expansion layer An inflatable sheet,
The thermal expansion layer is formed in multiple layers, and the content ratio of the predetermined white pigment to the thermal expansion material is larger in the layer farther than the layer closer to the base. Configured as
A thermally expandable sheet characterized by that. The predetermined white pigment is titanium oxide, barium sulfate or zinc oxide.
The thermally expandable sheet according to any one of claims 1 to 5, wherein: An ink receiving layer for receiving ink is provided on the thermal expansion layer.
The thermally expandable sheet according to any one of claims 1 to 6, wherein the sheet is thermally expandable. The ink receiving layer comprises porous silica;
The thermally expandable sheet according to claim 7. A base material and a thermal expansion layer formed on one surface of the base material, and the photothermal conversion by the heat photothermally converted by the photothermal conversion layer formed so as to overlap the thermal expansion layer A method for producing a thermally expandable sheet, wherein the portion of the thermal expansion layer overlapping the layer is thermally expanded to form irregularities on the surface,
On one surface of the substrate, the forming step of forming the thermal expansion layer containing heat-expandable material,
Have
The thermal expansion layer formed by the forming step is composed of a first thermal expansion layer and a second thermal expansion layer formed on the first thermal expansion layer,
A predetermined white pigment is contained only in the second thermal expansion layer of the first thermal expansion layer and the second thermal expansion layer.
A method for producing a thermally expandable sheet, characterized in that A base material and a thermal expansion layer formed on one surface of the base material, and the photothermal conversion by the heat photothermally converted by the photothermal conversion layer formed so as to overlap the thermal expansion layer A method for producing a thermally expandable sheet, wherein the portion of the thermal expansion layer overlapping the layer is thermally expanded to form irregularities on the surface,
A forming step of forming the thermal expansion layer containing a thermally expandable material in a multilayer on one surface of the base material,
Have
In the forming step, the predetermined white pigment is added so that the content ratio of the predetermined white pigment to the thermally expansible material is larger in the layer farther than the layer closer to the base. Containing the thermal expansion layer in multiple layers,
A method for producing a thermally expandable sheet, characterized in that A first forming step of forming a first thermal expansion layer containing the first thermal expansion material on one surface of the substrate;
A second formation step of forming a second thermal expansion layer containing a second thermal expansion material on the first thermal expansion layer formed by the first formation step;
A third formation step of forming a photothermal conversion layer for converting light into heat on the second thermal expansion layer formed by the second formation step;
By irradiating the photothermal conversion layer formed in the third forming step with light, heat is generated in the photothermal conversion layer, and the portion of the first thermal expansion layer overlapping the photothermal conversion layer is formed. And the second thermal expansion layer are thermally expanded to form irregularities on the surface;
Have
The second forming step includes a predetermined white pigment to form the second thermal expansion layer,
The first forming step forms the first thermal expansion layer without containing the predetermined white pigment.
The manufacturing method of the molded article characterized by this. A first forming step of forming a thermal expansion layer containing a thermally expandable material in multiple layers on one surface of the substrate;
A second formation step of forming a photothermal conversion layer that converts light into heat so as to overlap the thermal expansion layer formed in the first formation step;
By irradiating light to the photothermal conversion layer formed in the second forming step, heat is generated in the photothermal conversion layer, and the thermal expansion layer in a portion overlapping the photothermal conversion layer is thermally expanded. And a third forming step for forming irregularities on the surface;
Have
In the first forming step, the predetermined white pigment content ratio with respect to the thermally expandable material is increased in the layer farther than the layer closer to the base. A white pigment is included to form the thermal expansion layer in multiple layers;
The manufacturing method of the molded article characterized by this.

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